Anemia is a reduced level of circulating hemoglobin. It can be classified based on red blood cell size and color. Common causes of anemia include iron deficiency, blood loss, vitamin deficiencies, and chronic diseases. Surgical patients are often anemic due to blood loss or chronic illness. Investigating anemia involves considering potential causes through history, physical exam, blood tests, and imaging. Management depends on severity and cause but may include iron supplementation, vitamin replacement, treating underlying conditions, or blood transfusions in severe or emergency cases. Transfusion requirements differ for anemic versus acutely bleeding patients.

1. Anemia in Surgery
Okon E. E. MD

2. Outline
 Introduction
 Composition of blood
 Anemia
 Classification
 Clinical Effects
 Surgical & General hematology
 Investigating Anemia
 Management
 Conclusion/Summary’
 References

3. Introduction
 Anemia is defined as a reduced level of circulating Hb
 Composition
 Total blood volume – 5.5 litres
 Divided into Plasma & cells
 Three main types of cells
 Erythrocytes
 Hematocrit
 Leukocytes
 Thrombocytes

4. Plasma
 A protein-rich solution
 Carries the blood cells
 Transports nutrients, metabolites, antibodies
and other molecules between organs.

5.  All blood cells originate from pluripotentstem
cells in the bone marrow.
 Divide lymphoid stem cells and myeloid stem
cells

7.  Erythrocytes
 Transport oxygen via haemoglobin
 Biconcave disc shape
 Contain no nucleus or organelles
 Reticulocytes (immature erythrocytes) contain residual RNA
 Average lifespan is 120 days
 Broken down by macrophages within the spleen, liver
and bone marrow
 Synthesis stimulated by erythropoietin

8. Leucocytes
 Neutrophils
 Most abundant leucocyte (40–70%)
 Spend 14 days in the bone marrow but have
a half-life of only 7 hours in the
blood
 Lymphocytes
 Second most common leucocyte (20–50%)
 Important for specific immune response

9.  Monocytes
 These account for 15% of leucocytes
 Largest leucocyte, mobile phagocytic cell Important in
inflammatory reactions.
 Eosinophils
 Make up 5% of leucocytes
 Important defence against parasitic infections
 Basophils
 Thrombocytes

11. Anaemia
 Anaemia is the reduction in the
concentration of circulating haemoglobin
below the expected range for age and sex:
 Adult male: <13 g/dl
 Adult female: <11.5g/dl

12.  Acute or Chronic
 Causes
 Decreased production
 Increased loss

13. Classification
 Size: Microcytic, Normocytic and Macrocytic
 Colour: Normochromic or Hypochromic

14. Microcytic Hypochromic Anemia
 Thalassaemia
 Iron deficiency
 Malabsorption
 Chronic blood loss, usually gastrointestinal
(GI) or genitourinary (GU) tract
 Decreased dietary intake
 Increased demand

15. Surgical context
 MC Anemia in surgical practice – IDA
 Colon Ca – right colon: fecal occult blood test
 Stomach

16. Normocytic normochromic
 Acute blood loss - Surgical context: trauma, massive GI bleed
 Anaemia of chronic disease – Surgical context: Malignant disease
 ACD & IDA may co-exist
 Endocrine disease
 Malignancy
 Haemolytic anaemia
 Erythrocyte abnormality:
 Spherocytosis
 Elliptocytosis •
 Glucose-6-phosphatase dehydrogenase (G6PD) deficiency

17. Normocytic normochromic
 Haemoglobin abnormality
 Sickle cell anaemia
 Extrinsic factors:
 Disseminated intravascular coagulation (DIC)
 Infections
 Chemical injury
 Sequestration

18. Macrocytic Anemia
 Megaloblastic (interference with DNA synthesiscausing morphological
abnormalities)
 Folate deficiency
 Vitamin B12 deficiency
 Pernicious anaemia •
 Gastrectomy
 Ileal resection
 Crohn’s disease
 Drugs
 Azathioprine
 Hydroxyurea
 Methotrexate

19.  Non-megaloblastic anaemia
 Liver disease
 Alcohol
 Pregnancy
 Hypothyroidism
 Increased reticulocyte number

20. Clinical effectsof anaemia
 A slowly falling haemoglobin level allow for tissue acclimatisation –
Palpitations, angina, ear buzzing
 Tachycardia
 Asthenia, Lethargy, fatigue
 Increased cardiacoutput
 Reticulocytosis
 Can anemia be beneficial? Increased blood flow across capillaries:
critical illness

21. Surgical haematology
 Changes in haematology as a response to major surgery
 Leucocytosis (usually due to increase in neutrophil count
relative to lymphocytes)
 Relative anaemia:
 Chronic illness
 Blood loss
 Impaired erythropoiesis
 Decreased serum iron
 Relative thrombocytosis
 Increased acute phase reactants includingerythrocyte
sedimentation rate (ESR) and C-reactive protein (CRP)

22. Investigating anaemia
 History
 Acute or chronic blood loss (e.g menorrhagia, per
rectal bleeding or change in bowel habit)
 Insufficient dietary intake of iron and folate (e.g elderly
people, poverty, anorexia, alcohol problems)
 Excessive utilisation of importantfactors (e.g pregnancy,
prematurity)
 Malignancy Chronic disorders(e.g malabsorption states affecting
the small bowel)
 Drugs (e.g phenytoin, antagonises folate)


23. Investigating Anaemia
 Reticulocyte count
 Hemolysis - serum bilirubin (unconjugated), urinary
urobilinogen, haptoglobin and haemosiderin
 Bone marrow biopsy
 TFTs
 E,U,Cr
 LFTS

24. Investigating anaemia
 Folate levels – Red cell folate levels > Serum folate
 Iron studies
 Vitamin C & iron
 Investigate for causes of blood loss
 Upper & Lower GI endoscopy
 IVU, Cystoscopy

25. Management
 Emergency Surgery
 Transfusion
 Elective surgery – Reversible causes should be corrected
 Mildly anemic – may tolerate GA and sedation
 Profound Anemia – Transfusion & Iron supplementation
 ACD does not respond to hematinics; requires blood
transfusion

26.  Blood transfusion requirements for the anemic
patient are very different from those of the patient
with acute blood loss.
 During transfusion – caution with circulatory overload
and CCF
 Red cell concerntrates should be <14 days as these
have near normal levels of 2,3DPG

27.  Vitamin B12 deficiency – replace
 Folate 5mg tab daily

28. Conclusion
 Blood – is composed of Plasma and cells
 All blood cells originate from a hematopoietic stem cell.
 Major surgery can result in hematologic changes
 Anemia is not a diagnosis – Must be classified, investigated and
treated appropraitely
 Anemia can be beneficial in critical illness
 Transfusion methods differ per patient and red cell concentrates <14
days are preferred

29. References
 Pastest essential revision notes for surgery
 Essential Surgical Practice by Sir Alfred
Cushieri